Hyperball Pinball Machine

This is technically not a pinball machine, but more of a gun game.  I played one in the summer of  2006 that is owned by another RGP member, Mark Gibson.  He furnished photos of his machine for IPDB.ORG, and naturally, his is a really nice looking and playing machine.  Hyperball is equipped with 55 3/4" steel balls which you fire with a solenoid "Hypercannon".  The mechanism is capable of 250 rounds per minute, and the direction of firing is controlled by dual hand controllers.  This machine is very cool to play, and when one was offered on Ebay in a nearby location with no bids, I decided to bid on it, and won it for the opening price of $150.  The seller was nice enough to include an original manual and a spare ball feeder mechanism.

As I prefer, this machine was not initially working, but after a day's work on Veteran's day 2007, I was able to get it running.  Some things that I did were:
All these parts were in my spare parts supply.  Regarding the speaker installed, I found out on RGP that Hyperball comes with only one speaker, the one on the backbox.  This was a surprise to many who responded.  I decided to leave the one I added in place.

The backglass and the playfield were in excellent condition, every bulb and the shooter worked fine, but almost every plastic was broken on the machine.  Also, I needed three under playfield ball chutes, and the GI relay under the playfield.  Ken ("Kenbo" on RGP) was nice enough to send me these for only the shipping charges.

Modifying the shooter
When I played the machine for the first time, it seemed to me that the shots were going more left than expected.  The reason became clear when I removed the shooter from the machine: It was mushroomed (peened) by the many ball hits, and the face was at an angle.  This is perhaps why almost all of the plastics of this machine were broken when I received it.  There must have been many airballs in the past.

The original shooter.  The end has been peened back due to the many ball hits
(photos by Mark Gibson).

The shooter is a hollow shaft, and I started by drilling out the inside to make the inner shaft straight.  The size of the ID is 3/16".  I then tried various ideas to make a replaceable shooter tip.  In addition to being serviceable, I also wanted the tip to be softer than steel so that the new set of 3/4" balls that I had put into the machine would not be scratched up.  My first idea was to use a flat head bolt with a rubber pad.  However, I found that I would have to thread the inside of the shooter shaft to make sure the bolt would not shoot out after a few shots.  I then hit upon a simpler idea of making a rod out of a stiff rubber material, and then having a small amount protrude from the tip.

The inner bore drilled out, and the outer flange ground flat.  Also shown
is the rubber staff ready for use.

The modified shooter rod with the hard rubber tip.

Since the hard rubber is fairly light, it does not have enough inertia to shoot back out.  Also, I made the rubber strip long so that it bottoms out in the inner shaft.  The resulting performance was excellent.  Shots were consistently straight, and I know I have a durable replaceable tip that will not mark the balls.

Quieting the machine down
Hyperball is notorious for being noisy.  I spent some time finding ways to quiet this machine down.  To start, I used my Sound Pressure Level meter to obtain some quantitative results.  The meter was placed 16" from the left side in front of the yellow ball on the side art.  The game sound volume was then turned to minimum, and I played a game while observing the meter.  The resulting noise level peaked at 90 dB.  Per wikipedia, this is comparable to a major road at 10 meters.  This site also claims hearing damage at prolonged levels of 85 dB.

The SPL meter was set up 16" from the yellow ball on the left side art.

It was clear from simply listening to the machine that the loudest part is the bottom part of the ball feed mechanism.  Balls fall into the trough and rattle around noisily.  As a test, I padded that area with some rubber, and then found that the second loudest part was the top of the ball feeder, where the balls leave the auger.  I then decided to remove the entire mechanism to pad all the areas.  At first, I was going to use some rubber sheets, but I decided to use a material that slides easily so that if it came loose would not jam the auger screw (and possibly damage the motor).  The material I decided to use was adhesive felt that I bought from the craft store (Michael's).  They come in 8.5x11" sheets, and cost one dollar each.  They are easily cut with scissors, and the adhesive is very sticky.

The parts of the auger padded with black adhesive felt to quiet it down.

These are the areas of the machine that I padded.
  1. At the bottom of the auger feed trough, there are three metal surfaces that the balls touch.  These contributed the most noise.
  2. At the top of the auger, there is a small ramp that deflects the balls onto the trough of the playfield.
  3. The  path of the ball as it is lifted by the auger.  This path can be identified by a dark line eroded into the metal.
  4. The top part of the playfield trough that catches the balls from the auger.
  5. The angled part in the back of the subfloor where the balls hit when going through the gates.
  6. The part of the subfloor that get struck by the balls that drain from the two lowest points on the playfield.
  7. The backstop of the ball shooter as it retracts.
The final tally is a noise level that peaks at 81 dB.  Thus a reduction of sound power of almost a factor of ten.  Most of this reduction is due to the first three items above.  As a matter of fact, the loudest part of the feed trough is now the "click-click" of the balls touching each other, and as they hit the sides of the auger screw.  This portion is greatly reduced when the machine is closed.

Adding Auto-Fire
Truth be told, my fingers are not as nimble as they once were.  A few games on Hyperball will leave my trigger fingers quite sore.  As a result, I decided to add auto-fire to the right handcontroller button.  In this manner, the player has the option of single or auto-fire.  The circuit had to be small, and feature an isolated output so that it does not interfere with the switch matrix.  Its design is shown below.

Circuit to add auto-fire to the Hyperball handcontrollers.  The rate is controllable by R1.

All the parts were from my spare parts supply.  The circuit is simply a 555 timer with an optoisolator output that is controlled by the trigger button.  One important design requirement was to cause a fire immediately as soon as the trigger is pulled.  Any delay will impact the player's sense of control.  It would also allow the right button to be continued to be used as single fire (one pull, one shot).  This is accomplished by connecting the ground terminal of the timer to ground with the trigger switch.  Placing the switch in another location (in series with R1 or in series with the positive power line) would cause a brief delay before the first ball is fired.  Another benefit about this configuration is that the circuit consumes no current when the trigger button is released.

In addition to these previous connections, the optoisolator connects to the switch matrix with the row/column polarity as shown.  No diode is needed since the switch is a phototransistor.  The circuit is powered by the 5V and ground connection in the top left corner.  This supply comes from the opto supply on the playfield.  A connector on the circuit board allows this to be disconnected for removal of the handcontroller panel.

I also wished to be able to install the circuit by simply connecting it to existing connectors (for easy removal).  However, examination of the schematics showed that this would not be possible because the left and right handcontroller buttons share one wire.  The circuit was therefore installed by unsoldering the connections to the right handcontroller button and rewiring the panel accordingly.

The above circuit built onto a circuit board and then mounted onto the
handcontroller panel.  The board measures about 1.5" x 0.5".

To better show how the game plays, I shot a video of my daughter playing the machine.  At the beginning of the shot, you see her right hand, and that she is firing while holding down the right button.

Video showing how the Hyperball plays with the auto-fire feature.
(at the end, my daughter says: "Completed, and I have not taken a single hit yet").


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